refactor(i18n): pre-build lookup map for translations

packages/core/src/i18n/InternationalizationContext.ts

@@ -21,13 +21,15 @@
  */
 
 import {createContext} from 'react';
+import {getResolve} from './resolve';
 import type {Locale, MessagesByLocale, Overrides} from './types';
 
 export interface InternationalizationContextValue {
   locale: Locale;
   direction: 'ltr' | 'rtl';
   messages: MessagesByLocale;
   overrides?: Overrides;
+  translate: ReturnType<typeof getResolve>;
 }
 
 /**
@@ -39,5 +41,6 @@ export const InternationalizationContext =
     locale: 'en',
     direction: 'ltr',
     messages: {},
+    translate: getResolve('en', {}),
   });
 InternationalizationContext.displayName = 'InternationalizationContext';

packages/core/src/i18n/InternationalizationProvider.tsx

@@ -23,6 +23,7 @@ import {useMemo, type ReactNode} from 'react';
 import {InternationalizationContext} from './InternationalizationContext';
 import {getLocaleDirection} from './getLocaleDirection';
 import type {Locale, MessagesByLocale, Overrides} from './types';
+import {getResolve} from './resolve';
 
 export interface InternationalizationProviderProps {
   /**
@@ -79,7 +80,13 @@ export function InternationalizationProvider({
 }: InternationalizationProviderProps) {
   const direction = dir ?? getLocaleDirection(locale);
   const value = useMemo(
-    () => ({locale, direction, messages: messages ?? {}, overrides}),
+    () => ({
+      locale,
+      direction,
+      messages: messages ?? {},
+      overrides,
+      translate: getResolve(locale, messages ?? {}, overrides),
+    }),
     [locale, direction, messages, overrides],
   );
   return (

packages/core/src/i18n/__tests__/resolve.test.ts

@@ -9,9 +9,16 @@
  */
 
 import {describe, expect, test, beforeEach, vi} from 'vitest';
-import {__resetForTests, resolve, resolveLocaleChain} from '../resolve';
+import {__resetForTests, getResolve, resolveLocaleChain} from '../resolve';
 import type {Catalog, MessagesByLocale, Overrides} from '../types';
 
+const resolve = (
+  ...[key, values, locale, messages, overrides]: [
+    ...Parameters<ReturnType<typeof getResolve>>,
+    ...Parameters<typeof getResolve>,
+  ]
+) => getResolve(locale, messages, overrides)(key, values);
+
 // Reset caches between tests so warn-once and formatter cache don't bleed.
 beforeEach(() => {
   __resetForTests();

packages/core/src/i18n/resolve.ts

@@ -73,74 +73,71 @@ export function resolveLocaleChain(locale: Locale): Locale[] {
   return chain;
 }
 
-function lookup(
-  key: string,
+function getLookup(
   locale: Locale,
   messages: MessagesByLocale,
-  overrides: Overrides | undefined,
-): string | null {
+  overrides?: Overrides,
+): Record<string, string> {
+  const lookup = {} as Record<string, string>;
   const chain = resolveLocaleChain(locale);
-
   // 1 + 2. Overrides (most specific to least specific in the chain)
-  if (overrides !== undefined) {
-    for (const tag of chain) {
-      const value = overrides[tag]?.[key];
-      if (value !== undefined) {
-        return value;
+  for (const tag of chain) {
+    if (overrides?.[tag]) {
+      for (const [key, value] of Object.entries(overrides[tag])) {
+        if (lookup[key] === undefined && value !== null) {
+          lookup[key] = value;
+        }
       }
     }
-  }
-
-  // 3 + 4. Shipped catalogs (most specific to least specific)
-  for (const tag of chain) {
-    const entry = messages[tag]?.[key];
-    if (entry !== undefined) {
-      return entry.defaultMessage;
+    if (messages[tag]) {
+      for (const [key, value] of Object.entries(messages[tag])) {
+        if (lookup[key] === undefined && value?.defaultMessage !== null) {
+          lookup[key] = value?.defaultMessage;
+        }
+      }
     }
   }
-
-  // 5. Shipped en catalog — always present
-  const enEntry = EN_CATALOG[key];
-  if (enEntry !== undefined) {
-    return enEntry.defaultMessage;
+  for (const [key, value] of Object.entries(EN_CATALOG)) {
+    if (lookup[key] === undefined && value?.defaultMessage !== null) {
+      lookup[key] = value?.defaultMessage;
+    }
   }
-
-  // 6. Nothing found
-  return null;
+  return lookup;
 }
 
-export function resolve(
-  key: string,
-  values: Record<string, unknown> | undefined,
+export function getResolve(
   locale: Locale,
   messages: MessagesByLocale,
-  overrides: Overrides | undefined,
-): string {
-  const result = lookup(key, locale, messages, overrides);
-
-  if (result === null) {
-    // Fires ONLY when a key is missing from every source including the
-    // shipped `en` catalog — a real bug (typo, stale catalog, deleted key).
-    // Fallback to `en` from a non-en locale is expected and stays silent,
-    // matching the FormatJS / i18next default.
-    warnOnce(
-      `astryx-i18n:${locale}::${key}`,
-      'astryx-i18n',
-      `missing key: ${key} (locale: ${locale})`,
-    );
-    return key;
-  }
+  overrides?: Overrides,
+) {
+  const lookup = getLookup(locale, messages, overrides);
+
+  return (key: string, values: Record<string, unknown> | undefined) => {
+    const result = lookup[key];
+    if (result === undefined) {
+      // Fires ONLY when a key is missing from every source including the
+      // shipped `en` catalog — a real bug (typo, stale catalog, deleted key).
+      // Fallback to `en` from a non-en locale is expected and stays silent,
+      // matching the FormatJS / i18next default.
+      warnOnce(
+        `astryx-i18n:${locale}::${key}`,
+        'astryx-i18n',
+        `missing key: ${key} (locale: ${locale})`,
+      );
+      return key;
+    }
 
-  if (values === undefined) {
-    // Static string — skip the parser entirely for the common case
-    return result;
-  }
+    if (values === undefined) {
+      // Static string — skip the parser entirely for the common case
+      return result;
+    }
 
-  const formatted = getFormatter(result, locale).format(values);
-  // IntlMessageFormat.format returns string | (string | React elements) — we
-  // only ever pass string values so it will be a string; assert for the type
-  // system.
-  return formatted as string;
+    const formatted = getFormatter(result, locale).format(values);
+    // IntlMessageFormat.format returns string | (string | React elements) — we
+    // only ever pass string values so it will be a string; assert for the type
+    // system.
+    return formatted as string;
+  };
 }
 
 /**

packages/core/src/i18n/useTranslator.ts

@@ -19,9 +19,8 @@
  * - /packages/core/src/i18n/t.client.ts
  */
 
-import {use, useCallback} from 'react';
+import {use} from 'react';
 import {InternationalizationContext} from './InternationalizationContext';
-import {resolve} from './resolve';
 
 export type TranslatorFn = (
   key: string,
@@ -42,9 +41,5 @@ export type TranslatorFn = (
  */
 export function useTranslator(): TranslatorFn {
   const ctx = use(InternationalizationContext);
-  return useCallback(
-    (key: string, values?: Record<string, unknown>) =>
-      resolve(key, values, ctx.locale, ctx.messages, ctx.overrides),
-    [ctx.locale, ctx.messages, ctx.overrides],
-  );
+  return ctx.translate;
 }